Određivanje antioksidativne moći i kapaciteta usvajanja metala divlje borovnice (Vaccinium myrtillus L., Ericaceae) na području Crne Gore
Determination antioxidant activity and metal accumulation capacity of wild bilberry (Vaccinium myrtillus L., Ericaceae) from Montenegro
Докторанд
Brašanac, SnežanaМентор
Mutić, JelenaЧланови комисије
Tadić, VanjaManojlović, Dragan
Stanković, Dalibor
Метаподаци
Приказ свих података о дисертацијиСажетак
Crnoj Gori ima u obilju, i tradicionalno se koristi u ishrani ljudi ali i za pripremu ekstrakata i tinktura
u tretmanu dijabetesa.
S obzirom da borovnica sadrži različite koncentracije makroelemenata i mikroelemenata, koji
su važni kao esencijalni elementi u tragovima, ili su potencijalno toksični, zavisno od koncentracije,
posebna pažnja je usmjerena na sadržaj 16 elemenata, uključujući makroelemenata (Al, Ca, Fe, K i
Mg) i mikroelemente (As, Ba, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sr i Zn) u korijenu, stablu, listu i plodu
divlje borovnice i zemljišnim supstratima kako bi se procijenila biodostupnost i migracija elemenata
iz zemljišnih supstrata u korijen i određene nadzemne dijelove biljke.
Što se tiče toksičnih metala As nije detektovan u borovnici. Borovnica je pokazala i vrlo mali
stepen akumulacije Pb u svim dijelovima biljke što je od izuzetne važnosti, s obzirom da je BCR
sekvencijalna ekstrakcija potvrdila izuzetnu mobilnost a samim tim i biodostupnost Pb na ispitivanom
zemljišnom su...pstratu. U slučaju Cd nešto veći biokoncentracioni faktor se javlja kod korijena biljke,
mada je njegova vrijednost bila ispod jedinice. Ipak, vrijednost translacionog faktora ukazuje, što je
takođe vrlo važno, da se ovaj toksični mikroelement u značajnijoj mjeri transportuje do stabla nego
plodova i listova borovnice. Dobijeni translokacioni podaci vezani za ispitivane toksične metale,
pored biokoncentracionih vrijednosti pokazali su da se plod i listovi borovnice mogu bezbjedno
primjenjivati kako u ishrani stanovništva tako i u tradicionalnoj medicini.
Visoka bioakumulaciona vrijednost u plodu borovnice zabilježena je samo za K. Ono što je
interesantno je da ovaj makroelement jedini i pokazuje značajan stepen translokacije prema plodu
borovnice. Sa druge strane, Ca, Mg, K, Fe, Al, Sr, Ba, Mn, Cu i Zn se u vrlo značajnoj mjeri
transportuju od korijena do listova, dok su Ca, Mg, K, Sr, Ba, Mn i Zn takođe pokazali veliku
sposobnost akumuliraja u listu borovnice.
Dnevni doprinos Cr, Mn i Cu iz jedne porcije ispitivanih borovnica je vrlo značajan, s obzirom
na preporučene vrijednosti dnevne potrebe esencijalnih elemenata, prema direktivi Evropske unije. S
druge strane, konzumiranjem 100 g ispitivane borovnice unijeti toksični metali čini samo mali
procenat od maksimalno prihvatljivog na dnevnom nivou, što nam ukazuje da borovnica ne
predstavlja toksikološki rizik po zdravlje konzumatora.
Osnovni cilj ove teze bilo je i ispitivanje korelacije između hemijskog sastava i
antioksidativne moći ekstrakata divlje borovnice (lista i ploda) dobijenih različitim ekstrakcionim
postupcima: Soxhlet ekstrakcijom, postupkom maceracije i ekstrakcijom vrelom vodom. Iako su
hemijski profil i antioksidativni kapacitet borovnice prilično ispitani, ovo je prvo istraživanja o
njihovoj korelaciji u različitim ekstraktima lista i ploda borovnice.
Uzimajući u obzir da se biljni vodeni infuzi najčešće koriste za pripremu tradicionalnih
fitopreparata, ali uzimajući u obzir i činjenicu da industrijska proizvodnja obično koristi etanol kao
rastvarač, koristili smo različite metode ekstrakcije i rastvarače različitih polarnosti za nalaženje
pogodnih uslova za dobijanje ekstrakata bogatih polifenolima.
Ovo istraživanje je potvrdilo da su ispitivani ekstrakti lista i ploda borovnice izuzetno bogati
fenolnim jedinjenjima i da posjeduju visoku antioksidativnu aktivnost mjerenu dvjema
spektrofotometrijskim metodama čiji rezultati su potvrđeni takođe i cikličnom voltametrijom. Naši
ekstrakti pokazali su visok stepen korelacije između sadržaja fenola, tanina, flavonoida, antocijana,
procijanidina, makroelemenata i mikroelemenata i njihove antioksidativne aktivnosti.
U ovom istraživanju, potvrđen je i veliki uticaj primjenjenog postupka ekstrakcije na sadržaj
fenolnih jedinjenja u ispitivanim ekstraktima. HPLC analizom u ispitivanim ekstraktima lista i ploda
borovnice identifikovano je osamnaest fenolnih jedinjenja, u različitim količinama, koji su u literaturi
prepoznati kao nosioci antidijabetskog potencijala. Najzastupljenija fenolna kiselina u ekstraktima
bila je hlorogenska kiselina, praćena protokatehinskom kiselinom, dok su u značajnim količinama u
ispitivanim ekstraktima zastupljeni i resveratrol, izokvercetin, kvercetin, hiperozid...
The subject of our research was investigation of different extracts of bilberry, (Vaccinium
myrtillus L, Ericaceae), a plant widespread in Montenegro, traditionally used in the treatment of
diabetes, but also recognised as valuable nutraceutical.
As bilberry is a source of macroelements and microelements in different concentrations, one
of the aims of this investigation was to determine the concentrations of 16 elements including macro
(Al, Ca, Fe, K and Mg) and microelements (As, Ba, Cd, Co, Cu, Cr, Mn, Ni, Pb, Sr and Zn) in roots,
stems, leaves and fruits of wild bilberry and corresponding soil sample in order to investigate element
mobility and availability in soil and the manner of translocation of elements taken up from the soil to
the roots and the above-ground parts of the plant. Depending on the concentration, the abovementioned
elements might be present in traces, representing the essentuials metals necessary for
regular metabolic process, but being present in greater quantiti...es they can be potentially toxic.
Regarding toxic metals, As was not detected in bilberry. Pb had also low bio-concentration
factor in all the parts of bilberry, which is extremely important, because the obtained results of applied
BCR sequential extraction procedure revealed that Pb could be considered as the most easily
mobilized metal in investigated soil samples. In the case of Cd, a slightly higher bioconcentration
factor occurs at the roots of the plant, although its value was below one. However, the value of the
translation factor indicates, which is also very important, that this toxic microelement is translocated
to the stems mostly but not to leaves or fruits. The obtained translocation data related to the researched
toxic metals, in addition to bio-concentration values, shows that the fruits and leaves of bilberry may
safely be used in both human nutrition and traditional medicine.
The high bioconcentration value in the fruits was only found for K. Interestingly, this is the
only element that has showed a significant level of translocation to the fruits. On the other hand, Ca,
Mg, K, Fe, Al, Sr, Ba, Mn, Cu and Zn were mostly translocated from roots to leaves, while Ca, Mg,
K, Sr, Ba, Mn and Zn also exhibited a high capability to be accumulated in leaves.
The daily contribution of Cr, Mn and Cu from one portion of the examined bilberry was very
significant, considering the recommended daily allowance values of these essential elements, in
accordance to the Directive of European Union. On the other hand, by consuming 100 g of tested
bilberry, the intake of toxic elements was only a small percentage of the maximum tolerable daily
intake, which indicates that bilberry possessed no toxicological risk to the consumer’s health.
Taking into account the abovementioned, the additional aim of this study was to investigate
the correlation between chemical profile and antioxidant activity of wild bilberry extracts (leaves and
fruits), obtained by different extraction procedures, namely Soxhlet extraction, maceration and
infusion. Although bilberry have been described elsewhere in terms of their chemical profile and/or
their antioxidant capacities, this the first research focusing on their correlation in different types of
bilberry leaves and fruits extracts.
Althoughthe water herbal infusions are most often used for preparation of traditional
phytopreparations, the industrial scale production usually employes ethanol as a solvent, different
extraction methods and solvents with different polarity were used to establish the suitable conditions
for obtaining the extracts rich in polyphenolic composition.
Our results revealed that all investigated bilberry leaves and fruits extracts were rich in
phenolic compounds and demonstrated good antioxidant activity measured by using two
spectrophotometric methods, the results verified with the cyclic voltammetry tests, as well. Our
extracts showed a high degree of correlation between phenols, tannins, flavonoids, anthocyanins,
procyanidins, macro and microelements content and their antioxidant activity.
This research also enabled to determine the effect of applied extraction procedure on the
phenolic content in examined extracts. Using a HPLC method, we confirmed the presence of eighteen
individual phenolic compounds in different amounts in the leaves and fruits extracts, known from the
up to date literature data to possess antidiabetic potential...